A simple RP-HPLC method for the determination of curcumin in commercial turmeric herbal products

Background: Curcumin derived from the dried rhizomes of turmeric has been extensively studied due to its wide range of biological activities and pharmacological effects. Previously reported HPLC methods have several disadvantages such as long run time, high flow rate, higher limits of detection and quantification, complicated mobile phase compositions with gradient elution and very low pH conditions. Purpose: To develop a simple, rapid, economic, precise and accurate reverse phase high performance liquid chromatographic method for the quantitative determination of curcumin in various commercially available turmeric/curcumin products and turmeric extracts. Method: Chromatographic separation was achieved using a Phenomenex Luna C18 column (150 x 4.6 mm; 5 µm) at 40 °C, with a mobile phase consisting of acetonitrile: 0.1% formic acid (50:50), at a flow rate of 0.8 ml/min. The detection was performed at 425 nm using photodiode array detector. Results: The developed method was validated in accordance with International Conference on Harmonization (ICH) guidelines. All the system suitability parameters were within the acceptable limits. Calibration curve was linear over the concentration range of 2-64 µg/mLwith correlation coefficient values of 0.999. The % RSD values for intraday and interday precision were ranged from 0.06 to 1.67. The mean percentage recovery of curcumin was found be in the range between 99.83 and 103.97 which were within the acceptance limits. The content of curcumin in the commercial Haridra capsule was found to be 2.5 % w/w, which is in accordance with the literature Conclusion: The developed RP-HPLC method is appropriate for the analysis of curcumin in wide range of turmeric products and used for quality control of products that contain curcumin as main ingredient